An element parameter identification of an electric power system can provide data basis for data processing, computation analysis, online tests, fault diagnosis, working condition prediction, etc. of the electric power system and play an important role in increasing analysis and computation for an electric power system.
According to current element parameter method, the obtained element parameters are with large errors, and especially, the parameters of an electric transmission line are with relatively large errors. The actual measurement error can be above 30%, and the theoretical parameter error of IEEE is also around 20%. It seriously impacts the computational accuracy of programs such as state estimations, stability analysis, etc. of an electric power system, and may even cause wrong judgments.
In the patent “Data sampling method and system, as well as method and system applying the data sampling method and system to parameter identification” (CN Application No. CN201210408534.9), the obtained sample sequence undergo a steady state processing after undergoing low-pass filtering and re-sampling, and then static parameters of the system are identified. Such method for identifying an element parameter of an electric power system is impacted by measurement errors, especially impacted by a current transformer (CT) error and a potential transformer (PT) error, causing deviation of the identified element parameters.